Systems and methods for fabricating composite fiberglass laminate articles

ABSTRACT

A method of fabricating a composite article comprising the following steps. A plurality of support templates is provided. The support templates are arranged to define a shape of the composite article. A plurality of primary panels are provided, where each primary panel defines at least one edge, a first surface, and a second surface. The first surface of the plurality of primary panels is secured to the plurality of templates such that at least one edge of one of each the primary panels is adjacent to at least one edge of another of the primary panels and the primary panels conform to the shape of the composite article. The adjacent edge portions of adjacent primary panels are joined.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.10/617,164 filed Jul. 9, 2003 currently U.S. Pat. No. 7,112,299. Thecontents of related applications listed above are incorporated herein byreference.

FIELD OF THE INVENTION

The present invention relates to systems and methods for fabricatingfiberglass articles and, more particularly, to such systems and methodsthat allow composite fiberglass laminate articles to be fabricatedwithout the use of a mold.

BACKGROUND OF THE INVENTION

The term “fiberglass” is commonly used to refer to a relatively rigid,strong, and lightweight inert plastic material that combines a plasticmatrix with a fabric of glass filaments or fibers. An article made offiberglass material will be referred to herein as a “fiberglassarticle”. The fabric of filaments or fibers will be referred to hereinas “reinforcement fabric”. The plastic matrix is formed by a solidifiedmixture of resin and hardener. In the following discussion, the mixtureof resin and hardener will be referred to simply as resin when in liquidform.

Fiberglass articles are typically fabricated by laying a mat ofreinforcement fabric, saturating the mat with resin, and allowing theresin and reinforcement fabric to harden. When the resin andreinforcement fabric harden, they bond chemically and mechanically toform a relatively rigid structure.

Fiberglass articles are typically produced using a mold. The creation ofa mold for fiberglass materials is highly labor and/or capitalintensive, and molds are thus relatively expensive to produce. Once amold is created, alterations to the design of the fiberglass articlerequire either a new mold or expensive and time consuming changes to anto existing mold. The use of molds to fabricate fiberglass articles thussubstantially increases the costs of the fiberglass article, especiallywhen the mold costs cannot be amortized over a large number of products.

Fiberglass materials can be used alone or in conjunction with othermaterials to form a finished product. By itself, fiberglass material canbe formed with a mold and then removed from the mold to obtain thefinished article. The fiberglass material can also be combined withother materials in a variety of ways. For example, the fiberglassmaterial can be applied to an underlying structure to protect andstrengthen the underlying structure.

Layers of fiberglass materials may also be laminated together and/or incombination with other materials. For example, inner and outer layers offiberglass material can be combined with a core of another type ofmaterial. The material formed by a plurality of layers of fiberglassmaterial will be referred to herein as a “fiberglass laminate” material.The material formed by one or more layers of fiberglass material and alayer of another type of material will be referred to herein as a“composite fiberglass laminate” material. The present application is ofparticular significance when used to fabricate a fiberglass laminatearticle and/or a composite fiberglass laminate article.

The need exists for improved systems and methods for fabricatingfiberglass articles, including fiberglass laminate articles andcomposite fiberglass laminate articles that allow, but do not require,the use of a mold.

SUMMARY OF THE INVENTION

The present invention may be embodied as systems for or method offabricating laminate articles. A plurality of support templates isprovided. The support templates are arranged to define a shape of thecomposite article. A plurality of primary panels are provided, whereeach primary panel defines at least one edge, a first surface, and asecond surface. The first surface of the plurality of primary panels issecured to the plurality of templates such that at least one edge of oneof each the primary panels is adjacent to at least one edge of anotherof the primary panels and the primary panels conform to the shape of thecomposite article. The adjacent edge portions of adjacent primary panelsare joined.

BRIEF DESCRIPTION THE DRAWINGS

FIGS. 1A-1H are somewhat schematic, front elevation views depicting afirst embodiment of a fabrication system of the present invention;

FIG. 2 is a perspective view of a support structure that may be used bya second embodiment of a fabrication system of the present invention;

FIG. 3 is a perspective view of a primary or outer skin layer of thestack used by a fabrication system of a second embodiment of the presentinvention being supported by the support structure of FIG. 2;

FIG. 4 is a top plan view of an outer skin panel of the stack used bythe fabrication system of the present invention;

FIG. 5 is a top plan view of a core panel of the stack used by thefabrication system of the present invention;

FIG. 6 is an exploded view depicting the layers that are assembled toform the stack used by a first embodiment of a fabrication system of thepresent invention;

FIGS. 7 and 8 are end elevation cut-away views illustrating the vacuumsystem used by the second embodiment of the present invention;

FIGS. 9 and 10 are close up cut-away views of the stack before and aftera vacuum is applied to the stack of the second embodiment of the presentinvention;

FIG. 11 is an end elevation cut-away view illustrating the removal of aremovable portion of the stack of the second embodiment of the presentinvention;

FIG. 12 is a somewhat schematic, end elevation, cut-away view of a thirdembodiment of the present invention; and

FIG. 13 is a somewhat schematic, end elevation, cut-away view of afourth embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring initially to FIGS. 1A-H of the drawing, one example of afabrication system 10 constructed in accordance with, and embodying, theprinciples of the present invention will now be described. As shown inFIGS. 1A-H, the fabrication system is used to form a three-layer,two-panel composite fiberglass laminate part 12 comprising a primarylayer or outer skin 14 and a plurality of secondary layers including acore 16 and an inner layer or skin 18.

The terms “inner” and “outer” are used in this application to refer tothe particular laminate part 12 being manufactured. In example describedherein, the laminate part 12 is a boat hull, and the outer skin 14 formsthe outer surface of the boat hull, while the inner skin 18 forms theinner surface of the boat hull. However, the fabrication system 10 maybe used to fabricate other laminate parts, and the terms “inner” and“outer” are not intended to limit the scope of the present invention,especially in the context of parts other than boat hulls.

The exemplary outer and inner skin layers 14 and 18 are formed of afiberglass material, while the exemplary core layer 16 is not. Theexemplary laminate part 12 described herein is thus a composite laminatefiberglass article as generally described above. The exemplary corelayer 16 may be made of any number of materials, including syntheticfoams, wood, steel, fiberglass, or other material having desirableproperties. The exemplary core layer 16 is made of a layer of syntheticfoam that is typically sold in sheets.

While the exemplary composite laminate part 12 described hereincomprises three layers, the principles of the present invention may alsobe applied to a fiberglass laminate article comprising two layers or acomposite laminate fiberglass article comprising more than three layers.For example, some applications may not require an inner skin layer, andthis layer may be omitted. In other parts, only the outer and innerskins are required, and the core layer may be omitted. Yet other partsmay employ more than one core layer; the number of core layers may beincreased to increase thickness or to employ core layers havingdifferent properties (e.g., different structural or insulationproperties). In addition, one or more of the core layers may be formedof fiberglass material.

In addition, the primary layer 14 and each of the secondary layers 16 or18 may be, and typically are, comprised of a plurality of individualpanels. Each of the layers 14, 16, and 18 of the exemplary laminate part12 comprises two panels identified as panels 14 a and 14 b, 16 a and 16b, and 18 a and 18 b in FIGS. 1B-11.

The laminate part 12 is fabricated based on a previously created partdesign. Typically, but not necessarily, the part design is created as athree-dimensional computer model. Based on the part design, a supportstructure 20 comprising a plurality of support templates 22 is formed;only one of the support templates 22 is represented in FIGS. 1A-G. Thesupport templates 22 are typically, but not necessarily, arranged in aparallel spaced apart arrangement. The characteristics of the laminatepart 12 determine the size and shape of, and spacing between, thetemplates 22.

Once the support structure 20 is formed, the outer skin layer 14 isformed as shown in FIG. 1B. To form the exemplary outer skin layer 14,outer surfaces 30 a and 30 b of the panels 14 a and 14 b are secured tothe templates 22. Typically, liquid adhesives are used to secure thepanels 14 a,b to the templates 22, but other adhesives may be used aslong as they form an adequate bond yet release when desired. Innersurfaces 32 a and 32 b of the panels 14 a and 14 b are exposed when theouter skin layer 14 is formed.

Next, as shown in FIG. 1C, an optional seal 34 is formed along an edgejoint 36 between the panels 14 a and 14 b. The optional seal 34 is usedto prevent air flowing through the edge joint 36 during a vacuum baggingstep to be described below with reference to FIGS. 1F and 1G. In thiscase, the seal 34 may simply be formed by tape capable of maintaining anairtight seal under vacuum.

The seal 34 may also structurally reinforce the edge joint 36 when thedesign of the part 12 requires such reinforcement. When suchreinforcement is desired, the seal 34 may be formed by a layer ofreinforcement fabric impregnated with resin.

The seal 34 is thus optional in that a laminate part made according tothe principles of the present invention may not require reinforcement.In addition, if the primary layer of the laminate part comprises asingle panel, no edge joints are formed that require sealing tofacilitate the vacuum bagging process described below. In addition, evena laminate part formed of multiple primary layer panels might be vacuumbagged in a manner or sequence that does not require a seal to be formedat the edge joints.

Outer surfaces 40 a and 40 b of the core panels 16 a and 16 b are nextarranged against the inner surfaces 32 a and 32 b of the outer skinpanels 14 a and 14 b, respectively, as shown in FIG. 1D. Inner surfaces42 a and 42 b of the core panels 16 a and 16 b are exposed at thispoint. Face junctures 44 a and 44 b are formed between the surfaces 32 aand 40 a and 32 b and 40 b, respectively. An edge juncture 46 is formedbetween the core panels 16 a and 16 b.

Inner surfaces 50 a and 50 b of the inner skin panels 18 a and 18 b arethen arranged against the outer surfaces 42 a and 42 b of the corepanels 16 a and 16 b, respectively, as shown in FIG. 1E. Inner surfaces52 a and 52 b of the inner skin panels 18 a and 18 b are exposed at thispoint. Face junctures 54 a and 54 b are formed between the surfaces 42 aand 50 a and 42 b and 50 b, respectively. An edge juncture 56 is formedbetween the skin panels 18 a and 18 b.

Before the vacuum process depicted in FIGS. 1F and 1G, the combinationof the outer skin panels 14 a,b, core panels 16 a,b, and outer skinpanels 18 a,b is referred to as a stack; the stack is identified byreference character 60 in FIGS. 1E, 1F, and 1G. The stack 60 may be drylaid (without resin) or wet laid (with resin).

The stack 60 may optionally dry laid to test the fit of the variouspanels 14 a,b, 16 a,b, and 18 a,b. After it is determined that thepanels 14 a,b, 16 a,b, and 18 a,b fit properly, the dry stack would bedisassembled and then reassembled with resin applied to the facejunctures 44 a,b and 54 a,b to form the wet stack.

When the stack 60 is wet laid, a vacuum bag 62 is preferably secured tothe outer skin panels 14 a,b. In particular, the vacuum bag 62 istypically secured by double stick tape to the outer surfaces 30 a,band/or the inner surfaces 32 a,b of the outer skin panels 14 a,b.Because of the seal 34 formed as described above, the vacuum bag 62 andouter skin panels 14 a,b define a sealed vacuum chamber 64 when thevacuum bag 62 is secured to the outer skin panels 14 a,b.

Withdrawing air from the vacuum chamber 64 as shown in FIG. 1G causesthe vacuum bag 62 to collapse against the inner surface 52 of the innerskin layer 18. The vacuum bag 62 engages the core panels 16 a,b andinner skin panels 18 a,b to inhibit movement of the panels 16 a,b and 18a,b until the resin cures. The vacuum bag 62 thus helps maintain thepanels 16 a,b and 18 a,b substantially in alignment while the resincures.

The vacuum within the chamber 64 also removes air from the facejunctures 44 between the layers 14 and 16 and from the face junctures 54between the layers 16 and 18; this vacuum further causes resin to flowthrough the edge juncture 46 between the core panels 16 a,b and the edgejuncture 56 between the inner skin panels 18 a,b. The resin is thusevenly distributed throughout the wet stack 60 before the resin cures.Vacuum bagging the wet stack 60 thus creates a stronger bond between thecore panels 16 a,b and inner skin panels 18 a,b and reduces voids withinthe finished laminate part 12.

After the resin cures, the vacuum bag 62 is removed from the outer skinlayer 14, and the outer skin layer 14 is removed from the templates 22as shown in FIG. 1H. The outer surface 30 of the outer skin layer 14 issmooth, and the adhesive bond that secures the outer skin panels 14 a,bto the templates 22 are easily broken. A small amount of adhesiveresidue may need to be scraped off of the outer surface 30.

The panels 14 a,b and 18 a,b described above are fiberglass articlesthat may be created by any one or a combination of different techniques.In one form of the invention, the laminate article 12 may be fabricatedusing only panels 14 a,b and 18 a,b that are substantially planar, orflat, when manufactured. A part design that may be fabricated using edgejoined flat panels is conventionally referred to as having developablesurfaces.

Depending upon the characteristics of the panels used, the panelstypically can be bent within limits to allow the panels to form a gentlycurved surface. During the process of creating the stack 60, securingthe panels 14 a,b to the templates 22 maintains the curvature of thepanels 14 a,b. After the resin has cured, the various layers 14, 16, and18 maintain the curved surfaces of the individual panels, yielding alaminate part 12 having gently curved surface portions and relativelydiscontinuous surface portions at the edge joints 36 and 56.

In addition, the principles of the present invention may be applied tolaminate parts having either purely non-developable surfaces or acombination of developable and non-developable surfaces. For example,one or both of the panels 14 a and 14 b may be fabricated using a curvedmold. In this case, the panels 14 a and 14 b may be joined togetherusing the system 10 described herein to obtain the finished part 12having at least one non-developable surface portion.

The fabrication system 10 of the present invention thus allows thedesigner significant flexibility when designing the laminate part 12.The designer may use entirely developable surfaces to obtain a low costpart by using a limited number of flat panels. By decreasing the sizeand increasing the number of the panels (e.g., using thin strips), thedesigner can created a laminate part having developable surfaces thatapproximate a part having non-developable surfaces. The designer mayfurther create a laminate part mostly of developable surfaces, but usemolded panels to form non-developable surfaces on a certain portion ofthe part (e.g., bow or keel) where such surfaces are desirable. Inaddition, the designer may develop a part consisting entirely of moldedpanels defining non-developable surfaces.

Using the fabrication system 10, the designer may tailor the designbased on cost, timing, and other considerations. For example, a designermay design a relatively low-cost prototype part having all developablesurfaces to quickly test the basic viability of the design and thenlater refine the design using higher cost molded parts havingnon-developable surfaces.

Even if all of the panels used to fabricate a laminate part are molded,the use of the fabrication process 10 of the present invention may yieldan advantage as compared to a process using a traditional male or femalemold.

For example, the fabrication process 10 might be commercialized in thecontext of a design company and an independent panel fabricationcompany. The design company would design the laminate part based on theneeds of the end user. The part fabrication shop would only requirerelatively inexpensive manufacturing facilities and low cost labor forassembling the panels into finished parts. The panel fabrication companywould invest in highly specialized equipment (lay-up tables, CNCmachines) for the fabrication of panels and ancillary components such astemplates. The panel fabrication company would be optimized solely forthe fabrication of panels based on computer models supplied by a numberof design companies.

The fabrication system 10 of the present invention thus would optimizethe resources of both the design company and the panel fabricationcompany. The result is lower cost and better service for the end user ofthe laminate part.

Whether the panels are fabricated on a flat lay-up surface or in a mold,the fiberglass panels 14 a,b and 18 a,b can be fabricated usingconventional fiberglass techniques. In either case, the exposed surfacesof the finished laminate part are formed by contact with a smoothsurface. The smooth lay-up surface in turn yields a laminate part inwhich only the exposed edge junctures between panels must be finished.

In the case of the laminate part 12, the exposed surfaces 30 and 52 ofthe inner and outer layers 14 and 18 are substantially finished afterthe step shown in FIG. 1H. The edge junctures 36 and 56 at these exposedsurfaces 30 and 52 may require limited touch-up to fill, sand, and coatthese junctures 36 and 56. The labor involved in this touch-up will beminor and can be minimized by carefully forming and laying theindividual panels 14 a,b and 18 a,b. The majority of the area defined bythe surfaces 30 and 52 will require no touch-up work after the stepshown in FIG. 1H.

With the foregoing understanding of the basic operation of the presentinvention, the details of a second exemplary fabrication system 110 willnow be described with reference to FIGS. 2-11.

Referring now to FIGS. 2, 3, 6, and 7 of the drawing, generallyrepresented at 110 in those figures is a fabrication system constructedin accordance with, and embodying, the principles of a second embodimentof the present invention. As part of the fabrication system 110, a stack112 is formed on a support structure 120 as perhaps best shown in FIGS.6 and 11.

The exemplary support structure 120 comprises a support platform 120defining a support surface 122. The support platform 120 is illustratedas a table, but the support surface 122 can be formed on the ground, aconcrete pad, a building floor, or any other structure capable ofsupporting the weight of the stack 112 as will be described in furtherdetail below.

FIG. 2 also shows that the exemplary support structure 120 comprises aplurality of template members 124 arranged in a template array 126 onthe support surface 122. The template array 126 defines a part outline128 that generally corresponds to a surface of the part that willeventually be formed from the stack 112.

In particular, the fabrication system 10 is used to form a laminate part130 (FIG. 11). The size, dimension, and location of the templates 124are dictated by the design of the laminate part 130 to be manufactured.In particular, the templates 124 correspond to the cross-sectional shapeof the laminate part 130 at parallel spaced-apart locations along thepart 130.

Typically, but not necessarily, the laminate part 130 may be designedusing a three-dimensional computer modeling tool. Such tools allow thedesigner to create a three-dimensional model of a part and to generatecross-sectional views of the three-dimensional model. Thecross-sectional views of the three-dimensional model thus may be used tofabricate the templates 124.

The templates 124 can be cut from plywood or other sheet material usingconventional and commonly available techniques. The templates 124 aresupported in the array 126 also using conventional and easily availabletechniques. The support structure 120 thus can be easily manufacturedusing a pattern and simple cutting tools. However, the templates 124 andcan also be manufactured using computer aided manufacturing equipmentbased on the three-dimensional computer model of the laminate part 130,if used.

As shown in FIG. 11, the stack 112 comprises, and is used to form, thelaminate part 130. FIG. 11 also shows that the exemplary stack 112further comprises a removable portion 132 the composition and purpose ofwhich will be described in further detail below.

FIGS. 6-11 show that the laminate part 130 comprises a primary or outerskin or layer 134 and one or more secondary layers such as a core layer136 and an inner skin or layer 138.

As perhaps best shown in FIG. 3, the exemplary outer skin 134 is formedby a plurality of panels 134 a-h. These panels 134 a-h are supportedsuch that edge joints 146 are formed by adjacent panels. For reasonsthat will be described in further detail below, some and possibly all ofthese edge joints 146 may be covered with an airtight seal. While it maybe possible simply to use a non-structural seal such as duct tape,strength can be provided to the outer skin 134 by layering fiberglasstape 148 (FIGS. 7 and 8) and impregnating this tape with resin to form astructural seal at the joints 146. In this case, the fiberglass tape 148may either be a mat or knitted tape depending on the strengthrequirements of the joint 146.

Referring for a moment to FIGS. 3, 6-9, and 11, the laminate part 130further comprises locator pegs 140 secured to the outer skin 134. Inthis exemplary fabrication system 110, the locator pegs 140 are adheredat one or more desired locations 144 on the inner surface 142 of theouter skin 134.

Although the exemplary fabrication system 110 uses glue or otheradhesive to secure the locator pegs 140 to the outer skin 134, othersystems and methods may be used. For example, the locator pegs 140 maybe inserted through or into holes or depressions formed in the outerskin 134 and then bonded to these holes or depressions. As anotherexample, locator pegs having integral clips may be used to secure thelocator pegs 140 along the edge of the outer skin 134.

As shown in FIGS. 5-8 and 11, locator holes 150 and 152 are formed inthe core 136 and inner skin 138, respectively. As will be described infurther detail below, the locator holes 150 and 152 are sized,dimensioned, and located such that these holes 150 and 152 each receiveone of the locator pegs 140 described above.

FIGS. 13-8 show that bleeder holes 154 and 156 are formed in the core136 and inner skin 138, respectively. The bleeder holes 154 and 156 areoptional, and the function of the bleeder holes 154 and 156 will bedescribed in further detail below.

Referring now more specifically to FIG. 3, it can be seen that thetemplates 124 support the eight outer skin panels 134 a-h. When theeight outer skin panels 134 a-h are joined together, the outer skin 134is formed as described above. In FIG. 3, only three of the templates 124are depicted, but it should be understood that the additional templatesare omitted for clarity.

Each of the outer skin panels 134 a-h can be manufactured on asubstantially flat composite lamination table using conventionaltechniques. The outer skin panels 134 a-h are thus flat panels that maybe held in a curved configuration when supported by the templates 124.To hold the panels 134 a-h in the curved configuration, these panels areadhered to the templates 124. The step of adhering the panels 134 a-h tothe templates may be omitted, however, if the panels 134 a-h do not needto hold a curve. Once secured by adhesives or the like placed on thetemplates 124, the outer skin panels 134 a-h are supported in the shapeof the outer surface of the boat hull to be formed by the laminate part130.

Turning now to FIG. 4, depicted therein is the panel 134 a forming alower bow portion of the hull formed by the laminate part 130. FIG. 4illustrates that three pegs 140 a-c are adhered at desired locations 144a-c on the inner surface 142 of the outer skin 134. As shown in FIG. 3,the remaining pegs 140 are secured at similar desired locations on theremaining panels 134 b-h. The pegs may be glued to the inner surface 142of the outer skin 134 as shown, may be inserted into holes formed in theouter skin 134, or attached using any other suitable means.

The point in the process at which the pegs 140 are attached to thepanels 134 a-h can vary depending on the nature of the laminate part130. These pegs 140 may be applied to the panels 134 a-h before assemblyof these panels 134 a-h into the outer skin 134 and/or after assembly ofthe outer skin 134. In the system 110, the pegs 140 are secured to thepanels 134 a-h after these panels 134 a-h are secured to the templates124 for cosmetic reasons.

The core 136 is formed by arranging a plurality of core panels withinthe outer skin 134. Not all of the core panels are shown in the drawing,but a core panel 136 a is shown in FIGS. 5, 7, and 8 and a core panel136 b is formed as shown in FIGS. 7 and 8. The shape of the core panel136 a (FIG. 5) generally conforms to the shape of the outer skin panel134 a (FIG. 4). In addition, the locator holes 150 a, 150 b, and 150 con the core panel 136 a correspond to the location of the pegs 140 a,140 b, and 140 c on the outer skin panel 134 a.

Accordingly, when the core panel 136 a is laid on to the outer skin 134,the locator holes 150 a-c are sized, dimensioned, and located to receivethe locator pegs 140 a-c. The locator pegs thus align the outline of thecore panel 136 a with the outline of the outer skin panel 134 a andsupport the core panel 136 a in a desired relationship with the outerskin panel 134 a. The remaining core panels are similarly supported bythe locator pegs 140 in desired relationship to the outer skin layer134.

With the core layer 136 formed as described above, the inner skin layer138 is next formed. In particular, like the outer skin layer 134 andcore layer 136, the inner skin layer 138 is formed by a plurality ofinner skin panels that are laid on the core layer 136. And like the corepanels, the panels forming the inner skin layer 138 have locator holes152 formed therein that are sized, dimensioned, and located to receivethe locator pegs 140. The locator pegs 140 engage the locator holes 152such that the inner skin panels are arranged in a desired orientationwith respect to the outer skin layer 134 and the core layer 136. Fromthe perspective shown in FIG. 5, the core layer 136 and inner layer 138look substantially the same.

At this point, the stack 112 comprises the outer skin layer 134, thecore layer 136, and the inner skin layer 138. Further, each of theselayers 134, 136, and 138 comprises a plurality of individual panels.

Referring now to FIGS. 6 and 11, these figures show that the removableportion 132 of the stack 112 is formed by a tear sheet 160, first andsecond bleeder sheets 162 and 164, and a breather sheet 166. As will bedescribed in further detail below, the bleeder sheets 162 and 164 andbreather sheet 166 create a pathway that allows air within the stack tobe withdrawn.

The tear sheet 160 is made of a material that does not bond with theresin used to form the finish laminate part 130. The tear sheet thusfacilitates removal of the removable portion 132 from the finishedlaminate part 130 as shown in FIG. 11. The exemplary tear sheet 160comprises tear sheet locator holes 170 that align with the locator pegs140 extending through the holes 152 in the inner skin 138. The tearsheet 160 further defines optional bleeder holes 172.

The locator holes 150, 152, and 170 in the core 136, inner skin 138, andtear sheet 160 are arranged relative to the bleeder holes 154, 156, and172 such that these bleeder holes 154, 156, and 172 are substantiallyaligned when the stack 112 is formed (FIG. 6). The bleeder holes 154,156, and 172 thus cooperate with the bleeder sheets 162 and 164 and thebreather sheet 166 to allow air trapped within the outer skin 134, core136, and inner skin 138 to be removed from the stack 112.

As perhaps best shown in FIGS. 7 and 8, the fabrication system 110further comprises a vacuum system 180. The vacuum system comprises avacuum bag 182 that is sealed to the outer skin 134 using double sticktape 184 to form a vacuum chamber 186. A vacuum port 188 is formed inthe vacuum bag 182 to allow the vacuum system 180 to establish a vacuumwithin the vacuum chamber 186.

The exact location of the double stick tape 184 will be determined bythe nature of the laminate part 130. In this case, the outer skin layer134 is slightly oversized such that it extends beyond the core layer 136and inner skin layer 138. The double stick tape 184 is arranged, asperhaps best shown in FIGS. 6-8 and 11, such that it extends around theentire periphery of the core layer 136, in the inner skin layer 138, andthe sheets 160-166 that form the removable portion 132 of the stack 112.The double stick tape 184 is typically applied with one liner sheet leftthereon while the stack 112 is being prepared.

The vacuum bag 182 is next secured to the double stick tape 184 todefine the vacuum chamber 186. In particular, the release liner isremoved from the double stick tape 184, and the vacuum bag brought intocontact with the exposed double stick tape 184 such that vacuum chamber186 is defined by the vacuum bag 182 and the outer skin layer 134. Thesealing of the joints 146 described above maintains the integrity of thevacuum chamber 186.

With the foregoing understanding of the formation of the stack 112 andthe vacuum system 180, the method of using the fabrication system 110will now be described. Initially, the outer skin 134 is formed. The corelayer 136 and inner skin layer 138 are then formed using the locatorpegs 140 to align and support the core layer 136 and inner skin layer138 on the outer skin layer 134. At the same time, a hardenable mixture190 is arranged between the outer skin 134 and the core 136 and, asnecessary, between the core 136 and the inner skin layer 138. Theremovable portion 132 of the stack 112 is then formed by inserting thelocator pegs 140 through the tear sheet locator holes 170.

The vacuum bag 182 is then secured to the double stick tape 184 suchthat the vacuum chamber 186 is formed as shown in FIG. 7. Then, as shownin FIG. 8, the vacuum system 180 is operated to establish a vacuumwithin the vacuum chamber 186. As shown by a comparison of FIGS. 9 and10, as the vacuum is formed, substantially all of the air that istrapped either between the outer skin layer 134 and the core layer 136or between the core layer 136 and the inner skin 138 is removed throughthe bleeder holes 154, 156, and 172. In this respect, the bleeder sheets162 and 164 and breather sheet 166 are air permeable such that thevacuum bag 182 does not seal itself against the tear sheet 160 andprevent from flowing out of the entire laminate part 130. The systemshould be operated such that substantially all of the air within thevacuum chamber 186 is evacuated before the hardenable mixture 190 sets.

Once the hardenable mixture 190 sets, the composite laminate part 130 isformed. The vacuum bag 182 is then removed, and the removable portion132 of the stack 112 is removed to leave the finished laminate part 130as shown in FIG. 11. In particular, at this point the templates 124 areremoved from the outer skin 134 by wedging, bending, or the like tobreak the bond therebetween.

At this point, the locator pegs 140 may be trimmed by grinding, sanding,or the like such they are flush with exposed surface of the inner skin138. Also, edge joints between adjacent panels of the inner and outerlayers 134 and 138 may be filled, sanded, and finished as necessary.

In addition, portions or the outer skin 134 may also be trimmed. Forexample, if the outer skin layer 134 is oversized to allow placement ofthe double stick tape 184 as shown in FIG. 11, this oversized portion ofthe outer skin layer 134 may be removed. In addition, a finish such asgel-coat may be applied to the all or a portion of the exposed surfacesof the inner and outer skins 134 and 138 if desired.

Referring now to FIGS. 12 and 13, depicted therein are third and fourthembodiments of fabrication systems constructed in accordance with theprinciples of the present invention. These embodiments disclose the useof the present invention in the context of a resin infusion process. Theresin infusion process is well-known and will not be described herein indetail.

In particular, FIG. 12 depicts a third exemplary embodiment of afabrication system 210. The fabrication system 210 employs a stack 212to fabricate a laminate part 220. FIG. 12 is somewhat schematic in thatgaps and channels formed by the stack 212 as described below areexaggerated.

The laminate part 220 comprises an outer skin 222, a core 224, and aninner skin 226. Locator pegs 230 extend from an inner surface 232 of theouter skin 222. As described above, the locator pegs 230 may be glued tothe surface 232 or otherwise attached to the outer skin 222. Locatorholes 240 and 242 are formed in the core layer 224 and inner skin layer226.

Outer channels 250 are formed between the core layer 224 and the outerskin 222, and inner channels 252 are formed between the core layer 224and the inner skin 226. The outer channels 250 and inner channel 252 canbe formed in several ways. First, a permeable breather sheet can bearranged on both sides of the core layer 224 between the core layer 224and the outer skin layer 222 and inner skin layer 226. Alternatively,the outer and inner channels 250 and 252 may be formed by texturing,forming grooves, or other physical change to the surface of the corepanels 224. The purpose of the channels 250 and 252 is to allow ahardenable liquid to flow through the stack 212.

A core gap 254 is formed where adjacent core panels 224 a and 224 bmeet, and an inner skin gap 256 is formed where inner skin panels 226 aand 226 b meet. Bleeder holes may also be formed in the core layer 224and inner skin layer 226, but the channels 250 and 252 and gaps 254 and256 may obviate the need for bleeder holes. Joints 260 between the outerskin panels 222 a and 222 b may be sealed by, for example, usingfiberglass tape 262 impregnated with resin.

A vacuum system 270 is formed by a vacuum bag 272. The vacuum bag 272 issealed to the inner skin layer 226 using double stick tape 274. A vacuumport 276 is formed in the vacuum bag 272 to allow access to a vacuumchamber 278.

The fabrication system 210 further comprises a resin supply system 280.The exemplary resin supply system 280 comprises one or more additionalvacuum bags 282 secured by double stick tape 284 over the edge of thelaminate part 220 to maintain a vacuum within the outer and innerchannels 250 and 252. Resin supply ports 286 extend through the vacuumbags 282 to allow a hardenable substance to flow into the channels 250and 252.

Establishing a vacuum within the vacuum chamber 278 and introducingresin through the resin supply ports 286 creates flow paths 290 for thehardenable substance introduced through the supply ports 286. Inaddition, the vacuum within the chamber 278 will remove air trappedbetween the core and the outer and inner skins 222 and 226 and evenlydistribute or disperse the resin in the channels 250 and 252 formed inthe face junctures on either side of the core layer 224. After thehardenable substance has set, the vacuum system 270 and resin supplysystem 280 may be removed leaving the laminate part 220.

Referring now to FIG. 13, depicted therein is yet another exemplaryembodiment of a fabrication system 310 of the present invention. Thefabrication system 310 uses a stack 312 to form a laminate part 320. Thelaminate part 320 comprises an outer skin 322, a core 324, and an innerskin 326.

As with the embodiments 110 and 210 described above, locator pegs 330are arranged in desired locations on the inner surface 332 of the outerskin 322. Similarly, locator holes 340 and 342 are formed in the core324 and the inner skin 326, respectively. As with the system 210, outerand inner channels 350 and 352 are formed on each side of the core 324between the core 324 and the outer and inner skins 322 and 326. A coregap 354 is formed between adjacent core panels 324 a and 324 b, while aninner skin gap 356 is formed between adjacent inner skin panels 326 aand 326 b. Joints 360 formed between panels forming the outer skin layer322 are sealed with tape 362 as generally described above.

The fabrication system 310 further comprises a vacuum system 370comprising a vacuum bag 372 and double stick tape 374. The vacuum bagdefines a vacuum port 376, and the double stick tape 374 seals thevacuum bag 372 to the outer skin 322 to define a vacuum chamber 378.

The exemplary fabrication system 310 comprises a resin supply system 380comprising a plurality of resin supply ports 382. The resin supply ports382 extend through the vacuum bag 372 and allow a hardenable substanceto flow into the outer and inner channels 350 and 352. Accordingly,establishing a vacuum within the vacuum chamber causes a hardenablesubstance such as resin to flow along flow paths 390 such that air isremoved from the channels 350 and 352 and resin is substantially evenlydispersed within these channels 350 and 352.

The present invention may be embodied in ways other than those describedabove. The scope of the present invention should thus be determined bythe following claims and not the foregoing detailed description of theinvention.

1. A method of fabricating a composite article comprising the steps of:providing a plurality of support templates; arranging the supporttemplates to define a shape of the composite article; providing aplurality of primary panels, where each primary panel defines at leastone edge, a first surface, and a second surface, and at least one of theprimary panels is a flat primary panel the first and second surfaces ofwhich are substantially planar and substantially parallel; providing aplurality of secondary panels, where each secondary panel defines atleast one edge, a first surface, and a second surface; providing aplurality of tertiary panels, where each tertiary panel defines at leastone edge, a first surface, and a second surface; bending the at leastone flat primary panel such that the first and second surfaces thereofare no longer substantially planar; securing the first surface of theplurality of primary panels to the plurality of templates such that atleast one edge of one of each the primary panels is adjacent to at leastone edge of another of the primary panels, and the primary panelsconform to the shape of the composite article; forming an inner skin byjoining the adjacent edge portions of adjacent primary panels; after theinner skin has been formed, arranging the plurality of secondary panelssuch that the first surfaces of at least some of the secondary panelsare adjacent to the second surfaces of at least some of the primarypanels, and at least one edge of each of the secondary panels isadjacent to at least one edge of another of the secondary panels;joining the second surfaces of at least some of the primary panels tothe first surfaces of at least some of the secondary panels adjacentthereto; forming a core by joining the adjacent edge portions of thesecondary panels; after the core has been formed, arranging theplurality of tertiary panels such that the first surfaces of at leastsome of the tertiary panels are adjacent to the second surfaces of atleast some of the secondary panels, and at least one edge of each of thetertiary panels is adjacent to at least one edge of another of thetertiary panels; joining the second surfaces of at least some of thesecondary panels to the first surfaces of the tertiary panels adjacentthereto; forming an outer skin having exposed edge junctures by joiningthe adjacent edge portions of the tertiary panels; finishing the outerskin of the composite article by finishing the exposed edge junctures ofthe tertiary panels; and removing the plurality of support templatesfrom the plurality of panels.
 2. A method as recited in claim 1, inwhich the step of joining the adjacent edge portions of adjacent primarypanels comprises the step of applying resin in a gap formed between theadjacent edge portions.
 3. A method as recited in claim 2, in which thestep of joining the adjacent edge portions of adjacent primary panelsfurther comprises the step of arranging reinforcing material across thegap formed between the adjacent edge portions.
 4. A method as recited inclaim 1, in which: the step of joining the adjacent edge portions ofadjacent primary panels comprises the steps of applying resin in a gapformed between the adjacent edge portions of the primary panels; thestep of joining the adjacent surfaces of the primary and secondarypanels comprises the step of applying resin between the adjacentsurfaces of the primary and secondary panels; and the step of joiningthe adjacent edge portions of the secondary panels comprise the step ofapplying resin in a gap formed between the adjacent edge portions of thesecondary panels.
 5. A method as recited in claim 4, in which the stepof joining the adjacent edge portions of adjacent primary panels furthercomprises the step of arranging reinforcing material across the gapformed between the adjacent edge portions.
 6. A method as recited inclaim 1, in which the step of joining the adjacent surfaces of theprimary and secondary panels further comprises the step of applying avacuum such that resin is drawn between these adjacent surfaces.
 7. Amethod as recited in claim 1, in which the step of arranging theplurality of secondary panels comprises the steps of: forming at leastone locator hole in at least one of the secondary panels; attaching atleast one locator peg to at least one of the primary panels; anddisplacing at least one of the secondary panels such that the at leastone locator peg extends into the at least one locator hole.
 8. A methodof fabricating a composite article comprising the steps of: creating acomposite article design, where the composite article design comprises aplurality of developable surface portions corresponding to a shape ofthe composite article; fabricating a plurality of primary panels basedon the composite article design, where each primary panel corresponds toone of the developable surface portions, and at least one of the primarypanels is a flat primary panel; fabricating a plurality of supporttemplates based on the composite article design, where each of theplurality of support templates defines at least one support edgeportion; fabricating a plurality of secondary panels based on thecomposite article design; fabricating a plurality of tertiary panelsbased on the composite article design; arranging the plurality ofsupport templates based on the composite article design such that thesupport edge portions conform to the shape of the composite article;bending the at least one flat primary panel; connecting the plurality ofprimary panels to the support templates such that at least one edgeportion of each of the primary panels is adjacent to at least one edgeportion of at least one other of the primary panels, and the pluralityof primary panels are arranged in the shape of the composite article;forming an inner skin by joining adjacent edge portions of the pluralityof primary panels; after the inner skin has been formed, arranging theplurality of secondary panels such that a surface of at least one of thesecondary panels is adjacent to a surface of at least one of the primarypanels, and at least one edge portion of each of the secondary panels isadjacent to at least one edge portion of another of the secondarypanels; joining the adjacent surfaces of the primary and secondarypanels; forming a core by joining the adjacent edge portions of thesecondary panels; after the core has been formed, arranging theplurality of tertiary panels such that a surface of at least one of thetertiary panels is adjacent to a surface of at least one of thesecondary panels, the finished surfaces of the plurality of tertiarypanels are exposed, and at least one edge portion of each of thetertiary panels is adjacent to at least one edge portion of another ofthe tertiary panels; joining the adjacent surfaces of the secondary andtertiary panels; forming an outer skin having exposed edge junctures byjoining the adjacent edge portions of the tertiary panels; removing theplurality of support templates from the plurality of primary panels; andfinishing the outer skin of the composite article by finishing theexposed edge junctures of the tertiary panels.
 9. A method as recited inclaim 8, in which the step of joining the adjacent edge portions ofadjacent primary panels comprises the step of applying resin in a gapformed between the adjacent edge portions.
 10. A method as recited inclaim 9, in which the step of joining the adjacent edge portions ofadjacent primary panels further comprises the step of arrangingreinforcing material across the gap formed between the adjacent edgeportions.
 11. A method as recited in claim 8, in which: the step ofjoining the adjacent edge portions of adjacent primary panels comprisesthe steps of applying resin in a gap formed between the adjacent edgeportions of the primary panels; the step of joining the adjacentsurfaces of the primary and secondary panels comprises the step ofapplying resin between the adjacent surfaces of the secondary panels;and the step of joining the adjacent edge portions of the secondarypanels comprise the step of applying resin in a gap formed between theadjacent edge portions of the secondary panels.
 12. A method as recitedin claim 11, in which the step of joining the adjacent edge portions ofadjacent primary panels further comprises the step of arrangingreinforcing material across the gap formed between the adjacent edgeportions.
 13. A method as recited in claim 8, in which the step ofjoining the adjacent surfaces of the primary and secondary panelsfurther comprises the step of applying a vacuum such that resin is drawnbetween these adjacent surfaces.
 14. A method as recited in claim 8, inwhich the step of arranging the plurality of secondary panels comprisesthe steps of: forming at least one locator hole in at least one of thesecondary panels; attaching at least one locator peg to at least one ofthe primary panels; and displacing at least one of the secondary panelssuch that the at least one locator peg extends into the at least onelocator hole.
 15. A method as recited in claim 1, in which the step offorming at least one of the plurality of tertiary panels comprises thesteps of: providing a form defining a smooth surface; and applyingmaterial to the form; and allowing the material to harden to define theat least one of the plurality of tertiary panels, where a portion of thematerial in contact with the smooth surface of the form defines thesecond surface of the at least one of the plurality of tertiary panels.16. A method as recited in claim 8, in which the step of fabricating atleast one of the plurality of tertiary panels based on the compositearticle design comprises the steps of: providing a form defining asmooth surface; and applying material to the form; and allowing thematerial to harden to define the at least one of the plurality oftertiary panels, where a portion of the material in contact with thesmooth surface of the form defines the second surface of the at leastone of the plurality of tertiary panels.